Water-insoluble phenol-formaldehyde-polyamines, method for making them, curing of polyepoxides and the resulting product

ABSTRACT

A water-insoluble curing agent for epoxy resins, made by mixing a major amount by weight of a water-insoluble propylene diamine chosen from the group consisting of the C 8  to C 20  fatty propylene diamines and the C 12  to C 15  ether propylene diamines with a minor amount by weight of a water-soluble polyamine suitable for rapid cure of epoxy resins, mixing the resulting mixture with a water-insoluble substituted phenol to give a water-insoluble reaction product, and then reacting said reaction product with formaldehyde. A novel cured epoxy resin is produced by reacting the agent with an uncured epoxy resin, and the reaction can be done in a wet environment or even under water.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application Ser. No.401,547, filed July 26, 1982, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to an improved method for curing epoxy resin andfor making an amine epoxy curing agent that enables the mixture of epoxyresin and its curing agent to be coated on underwater substrates andcured there and also to be coated on wet and damp surfaces and curedthere.

Most amine epoxy curing agents are water soluble or at least partlywater soluble. Their water solubility renders these prior-art curingagents ineffective for adequate cure of epoxy resins when they areeither coated underwater over a substrate or on wet surfaces, becausewhen such cure is attempted, the curing agent partially dissloves inwater. As a result, the mixture tends to slip around on the surface andnot adhere. In addition, the ratio of epoxy to curing agent has to bealtered considerably from the optimum, to accommodate an unknown amountof curing agent that will dissolve in water, and an additional amount ofcuring agent will therefor be needed. Even then, the results aregenerally unacceptable.

A good example of curing agents that are partially water soluble are thecommon amine-amide-dimer acid curing agents known as "polyamide curingagents"; an example of this is Versamid 125 made by Henkel. Thismaterial forms a soft jelly-like mass when mixed with water, due to itspartial water solubility. When one attempts to coat a mixture of epoxyresin and Versamid 125 under water or on wet surfaces, the coating slipsaround on the wet surface and cannot make a satisfactory film.

Satisfactory underwater coating, as well as coating on wet or moistsurfaces, can be obtained by using the invention described and claimedin my earlier U.S. Pat. No. 4,022,946. The curing agents set forth inthat patent are water insoluble or substantially so. Two types are setforth:

(1) amines of the formula ##STR1## in which R is chosen from the groupconsisting of ether radicals of which one of the alkyl or alkyleneradicals has at least eight carbon atoms, and

(2) a condensation product of a small proportion of a polyepoxide havinga plurality of vic-epoxy groups and containing only members of thegroups consisting of carbon, hydrogen, oxygen, and chlorine, and alarger proportion of the amine of (1) above.

However, the product of U.S. Pat. No. 4,022,946 has many drawbacks. Itshows erratic cure, often poor, under ordinary conditions and cures veryslowly under cold conditions. The cured film is often soft and low instrength; it exhibits poor chemical resistance and poor resistance tosolvents. Its application requires the use of a diluent, because theuncured mixture is very viscous. Propylene glycol, the usual diluent, isapproved for use in food handling areas, but it detracts from thedesired water insolubility. Finally, the product tends to be expensive,partly because it is usually used in its adduct form, and the adductedepoxy resin is expensive.

Among the objects of the present invention are: the provision of animproved epoxy-resin curing agent having improved water insolubility,and imparting improved water insolubility to the mixture of the resinand curing agent; the provision of an improved agent for curing epoxyresins under water and for adhering them to various substrates, both inmoist conditions and under water; the provision of improved cure underordinary conditions, with more reliability and predictability and betterresin adherence; the provision of a product that cures epoxy resins morequickly than comparable products under cold conditions; the provision ofa curing agent that imparts to the epoxy resin improved toughness andflexibility even when the curing is done under water, the cured filmalso having excellent chemical resistance and excellent solventresistance; the provision of a curing agent requiring no diluentsbecause it has in itself a sufficiently low viscosity, which iscontrollable; and the provision of a curing agent, usable with epoxyresins under wet or moist conditions, that is less expensive thancomparable curing agents.

SUMMARY OF THE INVENTION

The amine curing agent of this invention is essentially water insoluble.This water insolubility is an important property in enabling the mixtureof epoxy resin with the curing agent to coat underwater surfaces or wetsurfaces.

One ingredient of the amine curing agent is a long-chain water-insolublealkyl propylene diamine, such as tallow propylene diamine. A secondingredient is a water-insoluble alkyl- or aryl-substituted phenol. Thesetwo ingredients are combined by means of formaldehyde to give awater-insoluble polyamine that, when combined with an epoxy resin, coatswet surfaces very well. Reactions of amines or polyamines with phenolsby means of formaldehyde is well known, though I am not aware of othershaving reacted the water-insoluble amines with the water-insolublesubstituted phenols.

However, the curing agent as so far described exhibits slow curingproperties, so that in difficult curing conditions, such as in coldwater, the cure is too slow to be useful. In addition, the films may besoft and may exhibit a low degree of curing.

I have found that I can remedy these deficiencies by incorporating athird ingredient, namely a polyamine known to speed the curing andcross-linking process. This third ingredient is mixed with the alkylpropyldiamine before the reaction with the alkyl- or aryl-substitutedphenol. When the reaction is carried out, the fast-curing polyamines arelinked together simultaneously with the substituted phenol by means offormaldehyde.

A surprising result of this procedure is that, although the fast-curingpolyamines are in themselves water soluble, when they are linked to thelarge, water-insoluble molecule of the substituted phenol combined withthe long chain diamine, the entire molecule is substantially waterinsoluble.

The amine-phenol-formaldehyde reaction employing other amines andphenols is sometimes referred to as a Mannich Reaction, and many patentshave described this type of reaction. End products have been used forionexchange resins, for lubricating oil additives, for epoxy curingagents, and for many other uses.

In this invention, however, a unique epoxy curing agent that allowsunderwater application of the epoxy resin is made by use of a reactionthat may be classified as a type of Mannich reaction. The inventionmakes use of a large amount (by weight) of a long-chain,water-insoluble, propylene diamine, a large amount of a water-insolublesubstituted phenol, a smaller amount (by weight) of a rapid-curingsimple polyamine, and a small amount of formaldehyde. Expressed in molarterms, the two amines may be used in substantially equal amounts, butthe long-chain, water-insoluble amine is much heavier than the simplepolyamine; so much more of the long-chain amine is used, in terms ofweight.

These ingredients are combined in two stages. First, the two polyaminesare mixed with the substituted phenol. The phenol and polyamine reacttogether when mixed, forming a salt or complex. This salt or complex isthen mixed with formaldehyde (as aqueous formaldehyde or asparaformaldehyde). A mild exotherm takes place upon the addition of theformaldehyde. When the exotherm subsides, the reaction is complete, andthe water of condensation plus the introduced water is driven off byconventional means, such as distillation.

The incorporation of phenol or similar compounds with the polyamineenables the formaldehyde to react smoothly to give transparent,low-viscosity liquids which are excellent polyamine epoxy curing agents.

In contrast, it should be noted that if the attempt were made to reactformaldehyde with polyamines alone, a very vigorous exotherm would takeplace and an unusable, high-polymer gel would likely result.

ILLUSTRATIONS OF UNUSABLE REACTIONS

To illustrate the propensity of the reaction of polyamine andformaldehyde to give high exotherms and unusable high polymer gels, thefollowing reactions are shown:

To 103 g. (one mole) of diethylene triamine, H₂ NCH₂ CH₂ NHCH₂ CH₂ NH₂,in a glass reaction flask stirred with a paddle stirrer, was added 66 g.(two moles) of 91% paraformaldehyde. The temperature rose from 20° C. to140° C. in about one minute, while violent boiling and refluxing tookplace. The color changed from light yellow to red and considerableamount of dark brown, hard infusible gel formed.

As a second example, a 70% solution of hexamethylene diamine in waterwas stirred at room temperature while 37% formalin was added. A whiteinsoluble precipitate or gel formed at once throughout the whole mass,and the mass became quite warm. This white precipitate was insoluble inmany strong solvents and reagents, including epoxy resins.

This same type of hexamethylene diamine formaldehyde precipitate or gelis described in the book: Formaldehyde by J. Frederick Walker, thirdedition, Robert E. Krieger Publishing Co., page 364, where this samereaction is described "giving a colorless, voluminous, elastic productwhich is insoluble in water and organic compounds.

DESCRIPTION OF SOME PREFERRED EMBODIMENTS OF THE INVENTION

In contrast, as shown in the examples below of the present invention,the amines react smoothly with formaldehyde when they are first mixedwith the substituted phenol.

The approximate structure resulting from this reaction is: ##STR2## R¹and R³ may be present in various ratios their respective positions; inother words the product may be a mixture of specific compounds. R² willalways be present in a 1:1 ratio with the phenol ring.

R¹ is chosen from the group consisting of radicals of certainpolyamines, namely: ##STR3##

R² is chosen from the group consisting of alkyl or aryl groups on thering of the phenol, namely ##STR4##

R³ is a C₈ to C₂₀ fatty propylene diamine radical or a C₁₂ to C₁₅ etherpropylene diamine radical. The formula for these fatty propylene diamineradicals is R⁴ NH(CH₂)₃ NH--, where R⁴ is an alkyl of C₈ to C₂₀. Theformula for the ether propylene diamine radical is R⁵ O(CH₂)₃ NH(CH₂)₃NH--, where R⁵ is a C₁₂ to C₁₅ alkyl.

As is shown in the examples below, nonylphenol is a particularly goodphenol to use in this reaction because of its wide availability and lowcost. Also, nonylphenol contributes good flow properties to the finalepoxy mixture.

Hexamethylenediamine is a particularly good amine to use because itpromotes fast curing when included in the curing agents of thisinvention. This fast curing is apparently due to the fact thathexamethylenediamine is an extremely basic amine compared to otherpolyamines. This highly basic characteristic promotes reaction with theepoxide groups of the epoxide resin and hence effects curing underadverse conditions where other polyamines, being less basic do not curewith the same energy.

The basic characteristics can be measured by noting the basedissociation constants of the amines. The larger the base dissociationconstants, K_(B) 1 and K_(B) 2, the stronger the base. For example:

    ______________________________________                                                       K.sub.B 1                                                                              K.sub.B 2                                             ______________________________________                                        Hexamethylenediamine                                                                           7.19 × 10.sup.-3                                                                   5.78 × 10.sup.-4                            Ethylene diamine  5.5 × 10.sup.-4                                                                    3.6 ×10.sup.-7.                            ______________________________________                                    

Thus, K_(B) 1 for hexamethylenediamine is more than ten times as strongas K_(B) 1 for ethylene diamine, and the K_(B) 2 for the former is morethan a thousand times as great as for the latter.

However, it has been noted that hexamethylenediamine results in someyellowing of the cured epoxy resin. Where this yellowing isobjectionable, the use of diethylene triamine may be preferred.

A rather surprising aspect of the addition of formaldehyde to thesubstituted phenol-polyamine mixture is that the viscosity of the curingagent can be varied over a wide range merely by varying the amount offormaldehyde. As the amount of formaldehyde is a small portion of thetotal curing agent, the variation of the amount of formaldehyde does notgreatly alter the total composition. This means that, for example, achange in formaldehyde content from 5% to 10% can change the viscosityfrom one poise to eighty poises and so affords a very convenient way ofobtaining a desired viscosity.

Formalin and paraformaldehyde are equally suitable for the chemicalreaction with the phenol-polyamine combination. However,paraformaldehyde is preferred from the manufacturing aspect because itis a solid form of formaldehyde and does not introduce large amounts ofwater, as does formalin. The use of paraformaldehyde with thephenol-polyamine combination also results in a very short reaction timein the reaction kettle.

Among the suitable long-chain, water-insoluble diamines are what areknown "fatty propyl diamines" and "ether propylene diamines". The formergroup includes diamines made from tallow, tall oil, coconut oil, andoleic acid. The latter group includes tridecyl ether diamine and a C₁₂-C₁₅ ether diamine. Tallow propylene diamine is the least expensive andtherefore may generally be preferred.

The Adogen products of this type from Sherex are quite good. Othercompanies make identical fatty propylene diamines, such as Azko Chemie(formerly Armak) and Humko Chemical Division, Witco Chemical Corp.Sherex is the one of the few suppliers of ether propylene diamines.

The following two tables list preferable such diamines and gives some oftheir properties. In the headings giving the formulas, the R in thefatty propylene diamines is a C₈ to C₂₀ alkyl radical; the R in theether propylene diamines is a C₁₂ to C₁₅ alkyl radical.

                                      TABLE I                                     __________________________________________________________________________                   Secondary                                                                           Gardner                                                            Total                                                                              Tertiary                                                                            Color     Percent                                                                            Approx.                                             Amine                                                                              Amine 1963 Iodine                                                                             Moisture                                                                           Combining                                                                           Physical Appearance                 Description                                                                             Value                                                                              Value (Max.)                                                                             Value                                                                              (Max.)                                                                             Weight                                                                              @ 25°                        __________________________________________________________________________    A. FATTY PROPYLENE DIAMINES - RNH(CH.sub.2).sub.3 NH.sub.2 :                  Hydrogenated                                                                            325-355                                                                            160-175                                                                             5     5 Max.                                                                            1.0  165   White Flakes                        Tallow Propylene                                                              Diamine                                                                       Tall Oil Propylene                                                                      320-340                                                                            155-170                                                                             8    85 Min.                                                                            1.0  170   Amber Liquid                        Diamine                                                                       Coco Propylene                                                                          410-435                                                                            200-220                                                                             6    12 Max.                                                                            1.0  137   Amber Liquid                        Diamine                                                                       Tallow Propylene                                                                        325-350                                                                            155-175                                                                             5    30-45                                                                              1.0  165   Amber Solid                         Diamine                                                                       Oleyl Propylene                                                                         320-340                                                                            150-175                                                                             5    70-85                                                                              1.0  170   Amber Liquid                        Diamine                                                                       B. ETHER PROPYLENE DIAMINES - RO(CH.sub.2).sub.3 NH.sub.2 :                   Tridecyl  325-340                                                                            150-165                                                                             4         1.0  168   Amber Liquid                        Ether Propylene                                                               Diamine                                                                       C.sub.12 --C.sub.15                                                                     322 MIN.                                                                           151 MIN.                                                                            1         1.0  174   White Paste                         Ether Propylene                                                               Diamine                                                                       __________________________________________________________________________

                                      TABLE II                                    __________________________________________________________________________    Chain Length Composition of R Group                                           __________________________________________________________________________    A. FATTY PROPYLENE DIAMINES - RNH(CH.sub.2).sub.3 NH.sub.2 :                            Approximate Chain Length Composition of R Group (%)                 Description                                                                             C-8                                                                              C-10                                                                             C-12                                                                             C-14                                                                             C-16                                                                             C-18                                                                             C-18'                                                                            C-18"                                                                             C-20                                       __________________________________________________________________________    Hydrogenated        5 30 65                                                   Tallow Propylene                                                              Diamine                                                                       Tall Oil Propylene        3 49 43   5                                         Diamine                                                                       Coco Propylene                                                                           5  7 50 18 10  6  4                                                Diamine                                                                       Tallow Propylene    5 30 20 45                                                Diamine                                                                       Oleyl Propylene        5 20 75                                                Diamine                                                                       __________________________________________________________________________    B. ETHER PROPYLENE DIAMINES - RO(CH.sub.2).sub.3 NH(CH.sub.2).sub.3           NH.sub.2 :                                                                              Approximate Chain Length Composition of R Group (%)                 Description                                                                             C-12   C-13  C-14   C-15                                            __________________________________________________________________________    Tridecyl         99                                                           Ether Propylene                                                               Diamine                                                                       C.sub.12 -C.sub.15                                                                      25     39    21     15                                              Ether Propylene                                                               Diamine                                                                       __________________________________________________________________________

These fatty diamines are N-alkyl-1, 3-propylene diamines. Since thesediamines contain both primary and secondary amine groups, they arestrong bifunctional bases, exhibiting greater cationic surface activitythan the primary amine from which they are derived.

In addition, their adsorption characteristics enable them to bondstrongly to relatively negatively-charged surfaces such as metals,textiles, plastics, mineral ores, and the like. These adsorptioncharacteristics are carried over to and are present in the curing agentsof this invention, for the long-chain phenols have similarcharacteristics, and the two enhance each other.

The fatty propylene diamines presently commercially available arederived from tallow, tall oil, coconut oil, and oleic acid. Diaminesfrom other natural fats can be obtained.

The ether propylene diamines are derived from alcohols rather than fattyacids. The introduction of the ether linkage into the molecule rendersthese products more liquid than conventional fatty amines and gives themmuch lower pour points. The ether diamines show adsorptioncharacteristics and water insolubilities very similar to those of thefatty propylene diamines.

The ether propylene diamines commercially available are based on alkylchain lengths from C₈ -C₁₅.

Commercial grade hexamethylene triamine is a by-product of hexamethylenediamine manufacture. It is a dark liquid with the following composition:

Bis-hexamethylene triamine (BHMT): 20-30%

C-10 diamines: 15-25%

lower amines and nitriles: 5-10%

high boilers (relative to BHMT): 40-60%

DESCRIPTION OF SOME PREFERRED EMBODIMENTS

A typical procedure according to the present invention is to charge thesubstituted phenol and the polyamines into a kettle at room temperature.If the fatty propylene diamine is solid at room temperature, it ismelted and poured into the kettle. This may raise the mix temperaturesomewhat. When these chemicals are mixed, a salt or complex formsraising the temperature several degrees. Then paraformaldehyde is added,and the temperature is raised to about 75° C. At this temperature theparaformaldehyde begins to dissolve, and heating is discontinued, and amild exotherm raises the temperature to about 100° C. The exotherm soonsubsides leaving a transparent liquid containing some added water (ifany) and the water of reaction form the chemical combination of theparaformaldehyde with both the polyamine and the phenol.

Then the water is driven off, for example, by heating to 120° C.,sparging with nitrogen or applying a vacuum or a combination of spargingand application of vacuum. Once the water is removed, the reaction iscomplete. Typical reaction times are two to four hours.

The following examples illustrate the invention. In all examples themanufacturing process was as follows:

A glass reaction flask was fitted with a stainless steel paddle stirrer,thermometer, and distillation apparatus which can be used to distill atatmospheric pressure or under vacuum. The polyamines and substitutedphenol are added to the flask and are stirred a short time at roomtemperature until an exotherm takes place. Stirring is continued, andheat is applied. Paraformaldehyde (or formalin, if desired) is thenadded, and stirring and heating are continued until the temperature isabout 75° C. The heating is then discontinued, while a mild exothermtakes place and the paraformaldehyde dissolves. Heat is again applied todistill off the added water (if any) and the water of reaction. Vacuumis also used to speed removal of water.

A gel time test is preferably made to evaluate the curing properties.This may be done by mixing the completed curing agent with 50 g. ofliquid epoxy resin of the bisphenol diglycidyl ether type with a weightper epoxy of about 190. The amount of underwater curing agent used withthe 50 g. epoxy resin was about 50 g. and was only approximatelystoichiometric. The gel time at standard temperature is noted.

To find the optimum properties of any one mixture of curing agent andepoxy resin, several variations from the starting ratio should be made.

In order to evaluate the ability of an amino-epoxy mix to be coatedunder water and also, therefore, its ability to coat wet and dampsurfaces, a test was devised.

Fifty grams of a liquid epoxy resin (WPE 190) is mixed with fifty gramsof the amine curing agent. After thorough mixing, the container andmixed epoxy-amine are placed underwater. A test panel, for example asteel panel, is also placed underwater. A portion of the epoxy-amine mixis removed from the container by a spatula or similar object, and themix is spread onto the panel underwater to make a film on it. The testis passed if the film adheres well and does not pull away from thepanel. All the examples below passed this test.

The following examples illustrate the invention:

    __________________________________________________________________________    Propylene                       Para-       Viscosity                         Diamine         Fast Curing                                                                            Substituted                                                                          formalde-   at 25° C.                  (R.sup.3)       Amine (R.sup.1)                                                                        Phenol hyde (PF)                                                                            Yield                                                                              (Poises)                                                                           Appearance                   __________________________________________________________________________    12                                                                            Example                                                                       No.                                                                           1.   Tallow     70% hexa-                                                                              nonyl  99 g.  1271 g.                                                                            2.8  yellow                            propylene  methylene                                                                              phenol 91% PF           transparent liquid                diamine    diamine  550 g. 90 g. 100%                                         Adogen 570S                                                                              in water 2.5 moles                                                                            CH.sub.2 O                                         Sherex     415 g.          3 moles of                                         400 g.     (290 g. 100%)   CH.sub.2 O                                         125 moles  2.5 mole                                                            ##STR5##                                                                     R.sup.3 R.sup.1                                                          1.25 moles:2.5 moles                                                          400 g.:290 g.                                                                      Still more weight of R.sup.3 than R.sup.1.                               This shows R.sup.1, a phenol with R.sup.2, and R.sup.3 the main point of      the invention. This uses more nonyl phenol than the later                     examples use. However, note 3 moles of CH.sub.2 O. Note viscosity is 2.8      poise.                                                                        2.   Tallow     70% hexa-                                                                              nonyl  141 g. --   14.8 yellow                            propylene  methylene                                                                              phenol 91% PF           transparent liquid                diamine    diamine  550 g. 128 g.                                             Adogen 570S                                                                              in water 2.5 moles                                                                            100% CH.sub.2 O                                    Sherex     415 g.                                                                        (290 g. 100%)                                                                          moles                                                                2.5 mole                                                            ##STR6##                  4.25 moles of CH.sub.2 O                           400 g.                                                                        1.25 moles                                                               Example                                                                       No.                                                                           3.   Tallow     70% hexa-                                                                              nonyl  180 g. 1302 g.                                                                            62   yellow                            propylene  methylene                                                                              phenol 91% PF           transparent liquid                diamine    diamine  550 g. 164 g.                                             Adogen 570S                                                                              in water 2.5 moles                                                                            100% CH.sub.2 O                                    Sherex     415 g.          5.46 moles                                                    (290 g. 100%)   of CH.sub.2 O                                                 2.5 mole                                                            ##STR7##                                                                     400 g.                                                                        1.25 moles                                                               In other words, the viscosity can be adjusted by varying the CH.sub.2 O.      4.   Tall       70% hexa-                                                                              nonyl  2.56   512 g.    yellow                            oil propylene                                                                            methylene                                                                              phenol 91% PF           transparent liquid                diamine    diamine  250 g. 22.75 g.                                           Adogen 551 in water 1.14 moles                                                                           100% CH.sub.2 O                                    Sherex     90 g.                                                                         (62.5 g. 100%)  0.75 moles                                                    0.53 mole                                                           ##STR8##                                                                     188 g.                                                                        0.56 moles                                                               About same moles of R.sup.3 to R.sup.1 but weight ratio much more with        R.sup.3.                                                                      5.   Oleyl propyl                                                                             70% hexa-                                                                              nonyl  2.56   512 g.    yellow                            diamine    methylene                                                                              phenol 91% PF           transparent liquid                Adogen 572 diamine  250 g. 22.75 g.                                           Sherex     in water 1.14 moles                                                                           100% CH.sub.2 O                                               90 g.                                                                         (62.5 g. 100%)  0.75 moles                                                    0.53 mole                                                           ##STR9##                                                                     188 g.                                                                        0.56 moles                                                               About same moles of R.sup.3 to R.sup.1 but weight ratio much more with        R.sup.3.                                                                      6.   Hydrogenated                                                                             70% hexa-                                                                              nonyl  25.6   512 g.    yellow                            tallow     methylene                                                                              phenol 91% PF           transparent liquid                diamine    diamine  250 g. 22.75                                              Adogen 540 in water 1.14 moles                                                                           100% CH.sub.2 O                                    Sherex     90 g.                                                                         (62.5 g. 100%)  0.75 moles                                                    0.53 mole                                                           ##STR10##                                                                    188 g.                                                                        0.56 moles                                                               About same moles of R.sup.3 to R.sup.1 but weight ratio much more with        R.sup.3.                                                                      7.   Coco       70% hexa-                                                                              nonyl  25.6   512 g.    yellow                            diamine    methylene                                                                              phenol 91% PF           transparent liquid                Adogen 560 diamine  250 g. 22.75                                              Sherex     in water 1.14 moles                                                                           100% CH.sub.2 O                                               90 g.                                                                         (62.5 g. 100%)  0.75 moles                                          ##STR11## 0.53 moles                                                         150 g.                                                                        0.56 moles                                                               About same moles of R.sup.3 to R.sup.1 but weight ratio much more with        R.sup.3.                                                                      8.   Tridecyl   70% hexa-                                                                              nonyl  22 g.  366 g.                                                                             1.6  yellow                            ether      methylene                                                                              phenol 91% PF           transparent liquid                diamine    diamine  143 g. 20 g.                                                         in water 0.66 moles                                                                           100% CH.sub.2 O                                               83 g.                                                                         (58 g. 100%)    0.66 moles                                                    0.5 moles                                                     C.sub.13 H.sub.27O(CH.sub.2).sub.3NH(CH.sub.2).sub.3 NH.sub.2                 188 g.                                                                        0.56 moles                                                                    9.   Tallow     hexamethylene                                                                          nonyl  33 g.  396 g.                                                                             19   tan-brown                         propylene  triamine phenol 91% PF           transparent liquid                diamine    80 g.    143 g. 30 g.                                              160 g.     0.5 mole 0.66 mole                                                                            100% CH.sub.2 O                                    0.5 moles                  1 mole                                        10.  Tallow     diethylene                                                                             nonylphenol                                                                          49.5 g.                                                                              537 g.                                                                             6.5  tan-brown                         propylene  triamine 220 g. 91% PF           transparent liquid                diamine    52 g.    1 mole 45 g.                                              220 g.     0.5 mole        100% CH.sub.2 O                                    0.67 mole                  1.5 mole                                      11.  Tallow     Naminoethyle                                                                           nonylphenol                                                                          49.59  550 g.                                                                             10   tan-brown                         propylene  piperazine                                                                             220 g. 91% .PF          transparent liquid                diamine    65 g.    1 mole 45 g.                                              220 g.                     100% CH.sub.2 O                                    0.67 mole                  1.5 mole                                      12.  Adogen 585 2-methylpenta-                                                                         nonyl  33 g.  396 g.    tan-brown                         (R.sup.3)  methylene                                                                              phenol 91% PF           transparent liquid                (C.sub.12 -C.sub.15                                                                      diamine                                                            ether diamine)                                                                           58 g.    143 g. 30 g.                                              174 g.     0.5 mole 0.66 mole                                                                            100% CH.sub.2 O                                    0.5 mole                   1 mole                                        13.  Tallow     70% hexa-                                                                              teriary butyl                                                                        33 g.  396 g.    tan-brown                         propylene  methylene                                                                              phenol*                                                                              91% PF           transparent liquid                diamine    diamine  100 g. 30 g.                                              160 g.     83 g.    0.66 mole                                                                            100% CH.sub.2 O                                    0.5 mole   0.5 mole        1 mole                                        *This phenol is an inexpensive widely used phenol.                            14.  Tallow     70% hexa-                                                                              octyl  33 g.  396 g.    tan-brown                         propylene  methylene                                                                              phenol*                                                                              91% PF           transparent liquid                diamine    diamine  136 g. 30 g.                                              160 g.     83 g.    0.66 mole                                                                            100% CH.sub.2 O                                    0.5 mole   0.5 mole        1 mole                                        *This is also a common, commercially available phenol.                        __________________________________________________________________________

The table does not exhaust the permutations of the invention. Forexample, any of the amines named in the table can be used with any ofthe phenols and related compounds named therein. Also differentproportions can be used, depending on the results desired.

I claim:
 1. ##STR12## R¹ being chosen from the group consisting of:##STR13## R² being chosen from the group consisting of C₄ to C₁₂ alkylgroups and the phenyl group on the ring of the phenol, andR³ beingchosen from the group consisting of fatty propylene diamine radicals, R⁴NH(CH₂)₃ NH--, where R⁴ is a C₈ to C₂₀ alkyl radical, and etherpropylene diamine radicals, R⁵ O(CH₂)₃ NH(CH₂)₃ NH--, where R⁵ is a C₁₂to C₁₅ alkyl radical.
 2. The composition of claim 1 where the averagevalues of R¹ and R³ vary from 1:1.
 3. The composition of claim 1, inwhichR¹ is --NH(CH₂)₆ NH₂ and R² is C₉ H₁₉.
 4. The composition of claim3, in which R³ is tallow propylene diamine.
 5. The composition of claim3, in which R³ is chosen from the group consisting of tallow propylenediamine, tall oil propylene diamine, oleyl propylene diamine,hydrogenated tallow propylene diamine, and coco propylene diamine. 6.The composition of claim 2, in which R³ is tridecyl ether propylenediamine.
 7. The composition of claim 1, in whichR¹ is --NH(CH₂)₂NH(CH₂)₂ NH₂ and R² is C₉ H₁₉.
 8. The composition of claim 7 in which R³is chosen from the group consisting of tallow propylene diamine, talloil propylene diamine, oleyl propylene diamine, hydrogenated tallowpropylene diamine, and coco propylene diamine.
 9. The composition ofclaim 1, in whichR¹ is ##STR14## R² is C₉ H₁₉, and R³ is chosen from thegroup consisting of tallow propylene diamine, tall oil propylenediamine, oleyl propylene diamine, hydrogenated tallow propylene diamine,and coco propylene diamine.
 10. The composition of claim 1, in whichR¹is ##STR15## R² is C₉ H₁₉, and R³ is C₁₂ -C₁₅ ether propylene diamine.11. The composition of claim 1, in whichR¹ is --NH(CH₂)₆ NH--(CH₂)₆ NH₂,R² C₈ H₁₇, and R³ tallow propylene diamine.
 12. The composition of claim1, in whichR¹ is --NH(CH₂)₆ NH--(CH₂)₆ NH₂, R² C₄ H₉, and R³ tallowpropylene diamine.
 13. A cured epoxy resin consisting essentially of thereaction product of an uncured epoxy resin and the composition ofclaim
 1. 14. A method for making a curing agent for epoxy resins,comprising the steps of:mixing a major amount by weight of awater-insoluble propylene diamine chosen from the group consisting ofthe C₈ to C₂₀ fatty propylene diamines and the C₁₂ to C₁₅ etherpropylene diamines with a minor amount by weight of a water-solublepolyamine suitable for rapid cure of epoxy resins, mixing the resultingmixture with a water-insoluble substituted phenol to give awater-insoluble reaction product, and then reacting said reactionproduct with formaldehyde to give said curing agent.
 15. The method ofclaim 14 wherein said reacting step is followed by removal of anyresidual contained water.
 16. The method of claim 14 wherein saidformaldehyde is used in the form of dry powdered paraformaldehyde. 17.The method of claim 14 wherein said polyamine is one or more aminechosen from the group consisting of ethylene diamine, diethylenetriamine, triethylene tetramine, tetraethylene pentamine, hexamethylenediamine, hexamethylene triamine, cyclohexane diamine, 2-methylpentamethylene diamine, meta xylene diamine, and N-aminoethylpiperazine.
 18. The method of claim 14 wherein said propylene diamine istridecyl ether diamine.
 19. The method of claim 14 wherein saidpropylene diamine is tallow propylene diamine.
 20. The method of claim14 wherein said propylene diamine is chosen form the group consisting oftallow propylene diamine, hydrogenated tallow propylene diamine, talloil propylene diamine, coco propylene diamine, oleyl propylene diamine.21. The method of claim 14 wherein said substituted phenol is nonylphenol.
 22. A method for obtaining a cured epoxy resin coating;comprising following the last step of claim 14 with the steps of mixingthe curing agent with uncured epoxy resin and then applying theresultant mixture to a substrate and curing it there on by leaving itthere for the cure time.
 23. A method for curing an epoxy resin which isworkable not only on dry substrates but also on a moist substrate or onewhich may be underwater, comprisingmixing said epoxy resin with##STR16## R¹ being chosen from the group consisting of: ##STR17## R²being chosen from the group consisting of C₄ to C₁₂ alkyl groups and thephenyl group on the ring of the phenol, and R³ being chosen from thegroup consisting of fatty propylene diamine radicals, R⁴ NH(CH₂)₃ NH--,where R⁴ is C₈ to C₂₀ alkyl radical, and ether propylene diamineradicals, R⁵ O(CH₂)₃ NH(CH₂)₃ NH--, where R⁵ is a C₁₂ to C₁₅ alkylradical, coating said mixture on said substrate.
 24. The method of claim23 in which R³ is chosen from the group consisting of tallow propylenediamine, hydrogenated tallow diamine, tall oil propylene diamine, oleylpropylene diamine, and coco propylene diamine.
 25. The method of claim24 in which R² is nonylphenol.
 26. The method of claim 25 in which R¹ ishexamethylene diamine.
 27. The method of claim 25 in which R¹ isdiethylenetriamine.